Cutting tool assembly

ABSTRACT

A cutting tool assembly comprising a cutter body which mounts at each of its opposite sides on one end and at the proper cutting angles a relatively narrow rectangular shaped cutter blade and a triangular shaped cutter blade. These cutter blades are maintained in an operative position in engagement with each other by a clamping element that is releasably joined to the cutter body at an angle that is related to the cutter cutting angles. Support and locking provisions further facilitate maintaining this operative position. Between these cutter blades a holder for another cutter blade is supported on the cutter body. This latter cutter blade and the triangular shaped blades are aligned along with the rectangular shaped cutter blades so as to machine a plural surface profile on a work piece.

This invention relates to an improved cutting tool assembly.

The machining of certain types of work pieces with a profile thatrequires compound surfaces be turned; e.g., the crankpins of a vehicleengine crankshaft, presents several considerations including tool life,accuracy, the time required and the cost of the equipment. With thecrankpin as an example, to achieve accuracy with the acceptable toollife, a two step machining operation is required; i.e., a roughmachining step followed by a finish machining step. Therefore bothadditional equipment and time are needed to meet present mass productionrequirements. One of the reasons for this two step operation is the lackof an acceptable cutting tool. Single cutter blades with severaldifferent cutting edges have not been acceptable because if one cuttingedge is damaged, the entire cutting blade has to be replaced or anexpensive regrinding process is required.

With the foregoing in mind, a new and different cutting tool assembly iscontemplated that enables compound surfaces to be formed accurately on awork piece by a single step operation.

Further contemplated is a cutting tool assembly that is durable, easilyserviced and that can accurately and efficiently form plural surfaces ona workpiece with a plurality of cutter blades.

Also contemplated is a cutting tool assembly that utilizes a pluralityof cutter blades uniquely mounted so as to provide desired cuttingangles and also the proper overlap to accurately turn compound diameterand shoulder surfaces on a work piece.

Other objects include the provision of a cutting tool assembly that in anovel way maintains a plurality of cutter blades in place on a cutterbody so as to achieve enhanced tool life, accuracy and operationalefficiency and that can be used by present mass production equipment tomachine plural surface profiles.

The foregoing and other objects and advantages of the invention willbecome apparent from the following description and from the accompanyingdrawings, in which:

FIG. 1 is a side elevational view of a cutting tool assemblyincorporating the principles of the invention;

FIG. 2 is a top elevational view, looking in the direction of arrows2--2 in FIG. 1, of the cutting tool assembly shown positioned formachining a vehicle crankshaft;

FIG. 3 is a front elevational view of the cutting tool assembly lookingin the direction of arrows 3--3 in FIG. 1; and

FIG. 4 is a fragmentary enlarged view with parts removed of a portion ofthe cutting tool assembly as viewed in FIG. 2.

Referring first to FIG. 1, the numeral 10 denotes generally a cuttingtool assembly that is adapted for positioning relative to a rotatableworkpiece, such as a crankshaft 12. The cutting tool assembly 10 isadjustably mounted upon a block 14, which in a well known way can movethe cutting tool assembly 10 into and out of the cutting relationshipwith the crankshaft 12.

For example, the block 14 may be a part of a conventional feed mechanism(not shown) for some kind of a production line transfer machine or alathe. For purposes of demonstration and without limitation, thecrankshaft 12 is in the form of a forging and has, as seen in FIG. 2, acrankpin portion 16 which when unmachined, has the shape shown by thedashed line at 17. When machined by the cutting tool assembly 10, thecrankpin portion 16 will have the depicted profile including a crankpinsurface 18 and a shoulder clearance surface 20, each being machined to adifferent dimension and in one step as will become apparent.

The cutting tool assembly 10 has a cutter body 22 with a bottom V-shapedmounting surface 24, which is seated on the block 14, and a top surface26. The body 22 also has at its cutting end 28 a cutter blade mountingprovision in the form of a pair of substantially V-shaped slots 30.

Each of the V-shaped slots 30 has a seating surface 32, which isinclined forwardly at an angle 33, as viewed in FIG. 1, and outwardly atan angle 34, as seen in FIG. 3. Each V-shaped slot 30 also has extendingtransversely from the seating surface 32 as depicted in FIG. 4, aninside locating surface 35, an outside locating surface 36, and a rearsurface 38. In this embodiment each of these surfaces are eitherperpendicular to the seating surface 32 or tapered towards the seatingsurface to facilitate cutter blade retention.

Positioned in each of the slots 30 is a rectangular shaped side cutterblade 40 formed of a suitably hard machining metal, such as tungstencarbide, and preferably made to extremely close tolerances. With eachblade 40 substantially identical in shape and dimension, they can bediscarded when damaged and replaced with a new blade. Each of the cutterblades 40 has opposite parallel sides 42 and 44 and rounded cuttingedges 46. These edges 46 can have other than the depicted roundedcontour. The side cutter blades 40 when in place in the slots 30 engagethe outside locating surface 36 and the rear surface 38, which has acontour at 48 that conforms to the rounded cutting edges 46, but canhave other shapes. When in the operative position, the side cuttingblades 40 each extend beyond the side of the cutter body 22, as viewedin FIGS. 2 and 4.

Also for mounting purposes, a cutter blade support provision is includedin each slot 30 in the form of a cutter blade support member 50 that hasthe depicted triangular configuration. When the support members 50 arein position each engages the parallel side 44 of the associated sidecutter blade 40 and also the inside locating surface 34 of the slot 30.Thus, the support members 50 function somewhat as a wedge formaintaining the side cutter blades 40 in their operative positions. Thecutter blade support members 50 each have a through center opening 52for purposes to be explained.

A locking provision is provided for maintaining each of the cutter bladesupport members 50 in place. This provision includes, as illustrated inFIG. 3, a dowel pin 56 or the like that is received in a blind hole 58in the cutter body 22 and extends from the hole 58 upwardly and into thecenter opening 52 in the associated cutter blade support member 50. Thedowel pin 56 has a relatively loose fit in the hole 58 but a relativelygood sliding fit in the support member opening 52. To complete thelocking provision, set screws 60 are threadedly carried by the cutterbody 22 at point near the lower end of each of the dowel pins 56 andwhen tightened force the dowel pin 56 rearwardly and, accordingly, eachof the cutter blade support members 50 so as to form a wedgedrelationship with the slots 30 and the side cutter blades 40.

Positioned on each of the cutter blade supporting members 50 is anindexable front cutter blade 62 of a relatively thin triangular shape.The front cutter blades 62 are of the throw-away type being also formedof hard cutting material, such as tungsten carbide, and manufactured toextremely close tolerances. The front cutter blades 62 have a centeropening 64 and relatively straight cutting edges 66 and end cuttingedges 68 on all sides. When in the depicted FIG. 3 operative positioneach of the front cutter blades 62 engages the side 44 of the sidecutter blade 40 and the inside locating surface .[.34.]. .Iadd.35.Iaddend.of the slot 30 has the proper radial alignment with thecrankshaft 12.

If preferred the cutter blade support members 50 can be the same as thefront cutter blades 62 and thus, would provide an auxiliary cutter bladein event replacement of one of the front blades 62 was required becauseof damage. It is also possible to use a damaged front cutter blade 62 inplace of the support member 50.

For holding the front cutter blades 62 in the operative position withinthe slots 30, clamp elements 72 are provided. Each of these clampelements 72, as best observed in FIG. 1, has a cutter blade engagingsurface 74 with a depending pin 76 (FIG. 3), and rear inclined surface78 and an intermediate relieved portion 80. The depending pin 76 of eachclamp element 72 fits within the center opening 64 in a respective oneof the front cutter blades 62, whereas the rear inclined surface 78engages one of a pair of inclined or tapered surfaces 82 on the cutterbody 22. Each of the cutter body inclined surfaces 82 is formed with acompound angle that has the same angle of inclination outwardly as theseating surface angle 34 (see FIG. 3) and an angle of forwardinclination, as shown at 84 in FIG. 1. The angle 84 has a total angularextent equal to the sum of a predetermined angular amount and theforward inclination of the seating surface angle 33. Each of the clampelement inclined surfaces 78 has a complimentary inclination so as tohave a substantial area thereof in engagement with the inclined surface82 on the cutter body 22. Also, the clamp element cutter blade engagingsurfaces 74 have a relatively large area thereof in engagement with theface of the respective one of the front cutter blades 62 to facilitatemaintenance of the blades 62 in the operative position. The FIG. 1clamping position for each clamp element 72 is maintained by a suitableholding screw 86 which extends through an elongated opening 88 (FIG. 2)in the clamp element 72 and threadedly engages the cutter body 22. Theholding screw 86 is threaded into the cutter body 22 at an angle withthe same outward inclination as the seating surfaces 32 have in FIG. 3at the angle 34.

Referring again to FIG. 1, the angle 84 of the inclined surface 82 isselected so that when the holding screw 86 is tightened, the resolutionsof forces will be such that the cutter blade 62 is forced rearwardly andin the plane of the seating surface 32, thus facilitating the wedgingrelationship for holding both the front cutter blade 62 and the sidecutter blade 40 in their operative positions. If the angle 84 of thisinclined surface 82 is too steep; for example, perpendicular to the topsurface 26 of the cutter body 22, the clamp element 72, when forced intothe clamping position by the tightening of the holding screw 86 wouldtend to raise the cutter blade 62 from its viewed position in FIG. 1.Contrariwise, if the angle 84 of the inclined surface 82 is not steepenough, there will not be an adequate force imposed upon the cutterblade 62 to maintain it in its operative position. By way of example andwithout limitation, it has been determined that if the inclination ofthe seating surface angle 33 is 5°, then the angle at 84 should be 30°plus the 5° or 35°.

Completing the assembly is a holder 90 which is slidably positioned onthe top surface 26 of the cutter body 22. The holder 90 has extendingthe length thereof a depending center portion 92 (FIG. 3), which engagesa complimentary slot 94 in the top surface 26 of the cutter body 22 soas to provide sliding adjusting movement only in the direction towardsand away from the workpiece. This sliding adjusting movement can be madeby a differential screw 95, which threadedly engages both the holder 90and a bracket 96 suitably attached to the cutter body 22. The holder 90is releasably maintained on the cutter body 22 by one or more screws 97,which threadedly engage the cutter body 22. The holder 90 and the cutterbody 22 are both releasably fixed on the block 14 by a pair of elongatedscrews 98 that threadedly engage the block 14.

As viewed in FIG. 2, the holder 90 has a narrow front portion 100 thatextends between the two clamp elements 72. This narrow portion 100 hasan upper inclined surface 102 and at the end thereof a cutter bladereceiving slot 104 which can also be triangular shaped. This slot 104has a seating surface 106 (FIG. 1) on which is mounted a triangularshaped middle cutter blade 108 including a center opening 110. The blade108 can be of the indexable throw-away type and thus similar to thefront cutter blades 62 and is appropriately inclined by the seatingsurface 106 so that the proper cutting angles are provided and also soas to be in the required approximate radial alignment with the center ofthe crankpin portion 16.

For holding the middle cutter blade 108 in the operative position, aclamp element 112 is employed that is similar structurally andfunctionally to the clamp elements 72. This clamp element 112 has acutter blade engaging surface 114 provided with a depending pin 116 anda rear inclined surface 118. When in the FIG. 1 clamping position, thedepending pin 116 engages the center opening 110 in the middle cutterblade 108, the surface 114 is flush against the face of the blade 108,and the rear inclined surface 118 engages a top portion 120 of theholder 90. As with the clamp elements 72, the angular relationship issuch as to provide the proper restraining forces for urging the middlecutter blade 108 rearwardly in the plane of its seating surface 106. Asuitable screw 122 holds the clamp element 112 in the depicted position.

As viewed in FIGS. 1 and 2, the alignment of the front cutter blades 62and the middle cutter blades 108 respectively on the cutter body 22 andthe holder 90 takes into consideration the different plane location ofthe middle cutter blade 108 and is such that an uninterrupteddiametrical cut is made on the crankpin surface 18. Also, the bladesizes are selected to provide the FIG. 2 illustrated crankpin profile.As the cutting tool assembly 10 is fed into the crankpin portion 16, itwill be noted that the side cutter blades 40 and the front cutter blades62 have substantially more metal to remove than the middle cutter blade108. This the described cutting tool assembly 10 can accompllishaccurately in one step and without sacrificing durability. Also, it willbe noted that the end cutting edges 68 of the front cutter blades 62provide the crankpin surface 18 with the proper size fillet at 124 andthat the side cutter blades 40 provide the shoulder clearance surfaces20, which terminate in a larger diameter at a fillet 126. This surface20 and fillet 126 provide somewhat of a boss for facilitating theinstallation and positioning of the vehicle crank in the crankpinportion 16.

The single machining step is done with indexable throw-away cutterblades that can be replaced in a minimum amount of time without concernabout realignment. Furthermore, when the support members 50 are the sameas the cutter blades 62 they can serve as auxiliary blades and be usedto replace one of the damaged front cutter blades 62. The resolution ofthe forces with respect to the clamp elements 72 and the clamp element112 provide optimum holding forces that maintain the wedge likerelationship so that the cutting blades 62 and 40 cannot shift or moveso as to be damaged or damage the crankshaft 12 during the machiningoperation.

What is claimed is:
 1. A cutting tool assembly comprising a cutter bodyincluding a mounting surface and a cutting end having cutter blademounting means on opposite sides thereof, each mounting means includinga slot opening outwardly from the cutting end and being so arranged asto have a certain angular relationship with the mounting surface forestablishing desired cutting angles; the cutter body also including apair of inclined surfaces each displaced from a respective one of thepair of slots and being provided with an inclination having apredetermined relationship with the certain angular relationship of eachof the pair of slots; a pair of side cutter blades respectivelypositioned within the slots so that in the operative position thereofthe cutting edges thereof project from the side of the cutter body; apair of front cutter blades respectively positioned within the slots sothat in the operative position thereof each front cutter blade is in acertain cutting alignment relative to the other and a respective one ofthe side cutter blades and is also arranged so as to be in engagementwith a respective one of the pair of side cutter blades; and a pair ofclamp elements respectively adjustably positioned on the cutter bodyadjacent the pair of front cutter blades so as to have a predeterminedangular relationship with a respective one of the pairs of slots, eachclamp element in the clamping position thereof having an inclinedsurface in engagement with a respective one of the pair of inclinedsurfaces on the cutter body and a cutter blade engaging portion inengagement with a respective one of the pair of front cutter blades soas to maintain a respective one of the pair of front cutter blades and arespective one of the pair of side cutter blades in the operativepositions thereof for cutting a certain profile.
 2. A cutting toolassembly as described in claim 1, further including a holder removablypositioned on the cutter body and having a cutter blade mounted thereonso as to be in the operative position thereof and in cutting alignmentwith each of the pair of front cutter blades.
 3. A cutting tool assemblyas described in claim 2, further including a clamp element releasablypositioned on the holder and having a front portion engageable with theholder mounted cutter blade and a rear portion provided with an inclinedsurface engageable with the holder at a certain angle so as to maintainthe holder mounted cutter blade in the operative position thereof.
 4. Acutting tool assembly as described in claim 1, wherein each of the pairof slots are defined by a seating surface having a certain angularrelationship with the mounting surface for establishing the desiredcutting angles and inside and outside locating surfaces extendinglaterally from the seating surface and at a predetermined angle relativethereto, each of the pair of side cutter blades is positioned within arespective one of the pair of slots and in engagement with both theseating surface and the outside surface and each of the pair of forwardcutter blades is positioned within a respective one of the slots so asto be in engagement with both the inside locating surface and arespective one of the pair of the side cutter blades.
 5. A cutting toolassembly as described in claim 4, wherein the mounting means furtherincludes a pair of support members respectively positioned within thepair of slots and in engagement with the seating surface and arespective one of the pair of front cutter blades and a respective oneof the pair of side cutter blades.
 6. A cutting tool assembly asdescribed in claim 4, wherein the slots are each triangular shaped andeach of the pair of front cutter blades are indexable and alsotriangular shaped and have a central opening therein engageable with thecutter blade engaging portion of a respective one of the pair of clampelements.
 7. A cutting tool assembly as described in claim 1, whereinthe mounting means includes a pair of auxiliary cutter bladesrespectively positioned within a respective one of the pair of slots onthe seating surface thereof and in the operative position thereof inengagement both with a respective one of the pair of side cutter bladesand the outside locating surface, each auxiliary cutter blade having atriangular shape and having a central opening therein; the mountingmeans also including means locking each of the pair of auxiliary cutterblades in the operative position thereof; each of the pair of slotsbeing triangular shaped and defined by a seating surface having acertain angular relationship with the cutter body mounting surface forestablishing desired cutting angles and inside and outside locatingsurfaces each extending laterally from the seating surface and at apredetermined angle relative thereto; each of the pair of front cutterblades being indexable and interchangeable with the auxiliary cutterblades, each of the pair of front cutter blades also .Iadd.being.Iaddend.triangular shaped and having a central opening thereinengageable with the cutter blade engaging portion of a respective one ofthe pair of the clamp elements.
 8. A cutting tool assembly as describedin claim 7, wherein the locking means includes a pair of pin elementsextendable from the cutter body and into the central opening in arespective one of the pair of auxiliary cutter blades and screw meanscarried by the cutter body for locking each pin element into the lockingposition and accordingly a respective one of the pair of auxiliarycutter blades in the operative position thereof.
 9. A cutting toolassembly as described in claim 8, further including a holder removablypositioned in the cutter body and having a cutter blade mounted thereonso as to be in the operative position thereof and in cutting alignmentwith each of the pair of front cutter blades and a clamp elementreleasably positioned on the holder and having a front portionengageable with the holder mounted cutter blade and a rear portionprovided with an inclined surface engageable with the holder at acertain angle so as to maintain the holder mounted cutter blade in theoperative position thereof.
 10. A cutting tool assembly comprising acutter body having a mounting surface, a cutting end and a pair ofspaced apart triangular shaped slots opening outwardly from the cuttingend, each of the pair of slots being defined by a seating surface havinga certain forward inclination and a certain lateral inclination bothrelative to the mounting surface for establishing desired cutting anglesand inside and outside locating surfaces perpendicular with andextending from the seating surface; the cutter body also including apair of inclined surfaces each displaced from a respective one of thepair of slots and being provided with an inclination having a certainrelationship to the inclinations of the seating surface; a pair ofrectangular shaped side cutter blades respectively positioned within theslots and in engagement with both the seating surface and the outsidesurface of a respective one of the pair of slots so that in theoperative position thereof the cutting edges thereof project from theside of the cutter body; a pair of triangular shaped auxiliary cutterblades respectively positioned within the pair of slots, each of thepair of auxiliary cutter blades having a central opening and beingpositioned on the seating surface of a respective one of the pair ofslots and in engagement with both a respective one of the pair of sidecutter blades and the respective inside locating surface; a pair oftriangular shaped front cutter blades respectively positioned within theslots and having a central opening, each of the pair of front cutterblades being positioned on a respective one of the pair of auxiliarycutter blades and in engagement with both the inside locating surface ofa respective one of the pair of slots and a respective one of the pairof side cutter blades and aligned in the operative position thereof sothat the cutting edges thereof are in cutting alignment with each other;the pair of auxiliary cutter blades and the pair of front cutter bladesbeing interchangeable with each other; a pair of clamp elementsrespectively adjustably positioned on the cutter body adjacent the pairof front cutter blades so as to have an inclination relative to thecutter body mounting surface corresponding to the certain lateralinclination of the seating surfaces of the pair of slots, each clampelement in the clamping position thereof having an inclined surfaceengageable with a respective one of the pair of inclined surfaces on thecutter body and a cutter blade engaging portion in engagement with arespective one of the pair of front cutter blades and also in engagementwith the central opening in a respective one of the pair of front cutterblades so as to maintain a respective one of the front cutter blades anda respective one of the side cutter blades in the operative positionthereof; locking means for each of the pair of auxiliary cutter blades;the locking means including a pair of pin elements carried by the cutterbody and respectively extending into the central opening in the pair ofauxiliary cutter blades and screw means for locking the pair of pinelements in place so as to maintain a respective one of the auxiliaryblade cutters and a respective one of the side cutter blades in theoperative positions thereof; and a holder adjustably positioned on thecutter body and having an end portion thereof extending between the pairof front cutter blades, the end portions having a middle cutter blademounted thereon so as to be in the operation position thereof and incutting alignment with each of the pair of front cutter blades at apredetermined cutting angle so as to cooperate with the pair of sidecutter blades for developing a machining profile including an elongateddiameter portion and a shoulder portion laterally extending from thediameter portion, and a clamp element releasably positioned on theholder and having a front portion engageable with the holder mountedcutter blade and a rear portion provided with an inclined surfaceengageable with the holder at a certain angle so as to maintain theholder mounted blade in the operative position thereof. .Iadd.
 11. Acutting tool assembly of the type that is fed in one direction into aworkpiece during a machining operation to provide on the workpiece whenthe machining operation is completed a profile composed of at least twodistinct surfaces, comprising: a cutter body having sides and a cuttingend having cutter blade mounting means on opposite sides of said cuttingend, each mounting means including a slot opening outwardly from thecutting end, a pair of removable side cutter blades positioned withinthe respective slots so that in the operative position thereof thecutting edges thereof project from the side of said cutter body, a pairof removable front cutter blades positioned within the respective slotsso that in the operative position thereof a cutting edge of each frontcutter blade is in a certain cutting alignment relative to the otherfront cutter blade and to a cutting edge of a respective one of the sidecutter blades such that said front and side cutter blades will removematerial from a workpiece in machining thereon a profile composed of atleast two surfaces with said front cutter blades machining at least onesurface distinct from the surfaces machined by said side cutter blades,each cutter blade having sidewalls extending generally rearwardly of itscutting edge, said side and front cutter blades in each slot beingjuxtaposed, at least one cutter blade in each slot having a pair ofsidewalls converging generally rearwardly away from the outward openingof its associated slot and rearwardly from its cutting edge in adirection generally opposite to the direction in which its cutting edgeis fed into a workpiece with one of said converging sidewalls beingjuxtaposed with and bearing on a sidewall of the other cutter blade insaid associated slot to wedge both the cutter blades in said associatedslot, and means retaining each of said one cutter blades in theirrespective slots so as to maintain a respective one of the pair of frontcutter blades and a respective one of the pair of side cutter blades intheir respective slots in the operative positions thereof for cutting acertain profile. .Iaddend. .Iadd.
 12. A cutting tool assembly asdescribed in claim 11 further comprising a holder removably positionedon the cutter body and having a cutter blade mounted thereon so as to bein the operative position thereof and in cutting alignment with each ofthe pair of front cutter blades. .Iaddend..Iadd.
 13. A cutting toolassembly as described in claim 11 wherein each of the pair of slots aredefined by a seating surface and inside and outside locating surfacesextending laterally from the seating surface and at a predeterminedangle relative thereto, each of the pair of side cutter blades ispositioned within a respective one of the pair of slots and inengagement with both the seating surface and the outside surface andeach of the pair of forward cutter blades is positioned within arespective one of the slots so as to be in engagement with both theinside locating surface and a respective one of the pair of the sidecutter blades. .Iaddend..Iadd.
 14. A cutting tool assembly as describedin claim 13 wherein the mounting means further includes a pair ofsupport members respectively positioned within the pair of slots and inengagement with the seating surface and a respective one of the pair offront cutter blades and a respective one of the pair of side cutterblades. .Iaddend. .Iadd.
 15. A cutting tool assembly as described inclaim 13 wherein the slots are each triangular shaped and each of thepair of front cutter blades are indexable and also triangular shaped andhave a central opening therein engageable with a cutter blade engagingportion of the retaining means. .Iaddend..Iadd.
 16. A cutting toolassembly as described in claim 11 wherein each of the pair of slots istriangular shaped and defined by a seating surface and inside andoutside locating surfaces each extending generally transversely from theseating surface, the mounting means includes a pair of auxiliary cutterblades respectively positioned within a respective one of the pair ofslots on the seating surface thereof and in engagement both with arespective one of the pair of side cutter blades and the inside locatingsurface, each auxiliary cutter blade having a triangular shape andhaving a central opening therein, the mounting means also includingmeans locking each of the pair of auxiliary cutter blades in theoperative position thereof, each of the pair of front cutter bladesbeing indexable and interchangeable with the auxiliary cutter blades,and each of the pair of front cutter blades also being triangular shapedand having a central opening therein engagable with a cutter bladeengaging portion of the retaining means. .Iaddend. .Iadd.
 17. A cuttingtool assembly as described in claim 16 wherein the locking meansincludes a pair of pin elements extendable from the cutter body and intothe central opening in a respective one of the pair of auxiliary cutterblades and screw means carried by the cutter body for locking each pinelement into the locking position and accordingly a respective one ofthe pair of auxiliary cutter blades in the operative position thereof..Iaddend..Iadd.
 18. A cutting tool assembly of the type that is fed inone direction into a workpiece during a single step machining operationto provide on the workpiece when the single step machining operation iscompleted at least two distinct surfaces, comprising: a cutter bodyhaving at least one cutter blade mounting slot opening outwardly fromsaid cutter body, said mounting slot having at least two sidewalls atleast in part spaced from each other and converging generally rearwardlyfrom the outward opening of said slot in a direction generally oppositeto said one direction in which said cutter body is fed into a workpiece,first and second cutter blades each having a cutting edge thereon andsidewalls extending generally rearwardly of said cutting edge, saidfirst and said second cutter blades being removably juxtaposed in saidslot between the sidewalls thereof with said cutting edges displacedfrom each other to each produce in said single step machining operationa respective one of said two distinct surfaces, at least one of thecutter blades having a pair of sidewalls converging generally rearwardlyfrom said outward opening of said mounting slot and rearwardly from itscutting edge in a direction generally opposite to said one directionwith one of said converging sidewalls being juxtaposed with and bearingon a sidewall of the other cutter blade to wedge both said cutter bladesbetween said two sidewalls of said mounting slot, and means retainingsaid one cutter blade in said mounting slot in engagement with saidother cutter blade whereby both the cutter blades are retained on saidcutter body by a wedging action of said one cutter blade..Iaddend..Iadd.
 19. A cutting tool assembly as described in claim 18wherein said mounting slot is generally triangular shaped and one of thecutter blades received therein is indexable and also generallytriangular shaped. .Iaddend..Iadd.
 20. A cutting tool assembly asdescribed in claim 18 further comprising a cutter blade support memberadapted to underlie said one cutter blade and having generallyrearwardly converging surfaces thereof bearing on an associated sidewallof said mounting slot and the other cutter blade, and another meansretaining said support member in said mounting slot to wedge the othercutter blade and said support member between said two sidewalls of saidmounting slot, whereby the other cutter blade is firmly retained on saidcutter body. .Iaddend..Iadd.
 21. A cutting tool assembly as described inclaim 18 wherein said mounting slot has a seating surface thereinextending generally transverse of said sidewalls thereof with saidseating surface underlying and supporting the cutter blades. .Iaddend..Iadd.
 22. A cutting tool assembly as described in claim 18 wherein theother converging sidewall of said one cutter blade is juxtaposed withand bears on one of said converging sidewalls of said mounting slot andthe other sidewall of said other cutter blade is juxtaposed with andbears on the other of said converging sidewalls of said mounting slot..Iaddend..Iadd.
 23. A cutting tool assembly as described in claim 18wherein said cutter body has a cutter end and at least one side facegenerally transverse thereto, said mounting slot receives the firstcutter blade therein with the cutting edge thereof projecting from saidside face of said cutter body, and said mounting slot also receives thesecond cutter blade therein with the cutting edge thereof adjacent thecutter end of said cutter body in a predetermined alignment relative tothe cutting edge of the first cutter blade such that the cutter bladesmachine surfaces in a workpiece generally transverse to each other..Iaddend..Iadd.
 24. A cutting tool assembly as described in claim 23wherein said mounting slot has a seating surface therein extendinggenerally transverse of said sidewalls thereof with said seating surfaceunderlying and supporting the cutter blades. .Iaddend. .Iadd.
 25. Acutting tool assembly as described in claim 24 wherein said retainingmeans also urges at least one of the cutter blades into firm engagementwith said seating surface in said mounting slot. .Iaddend..Iadd.
 26. Acutting tool assembly as described in claim 23 further comprising acutter blade support member adapted to underlie said one cutter bladeand having generally rearwardly converging surfaces thereof bearing onan associated sidewall of said mounting slot and the othe cutter blade,and another means retaining said support member in said mounting slot towedge the other cutter blade and said support member between said twogenerally opposed sidewalls of said mounting slot, whereby the othercutter blade is firmly retained on said cutter body. .Iaddend..Iadd. 27.A cutting tool assembly as described in claim 26 wherein said mountingslot has a seating surface therein extending generally transverse ofsaid sidewalls thereof with said seating surface underlying andsupporting the cutter blades, and said support member is interposedbetween said one cutter blade and said seating surface. .Iaddend. .Iadd.28. A cutting tool assembly as described in claim 27 wherein saidfirst-mentioned retainer means also urges at least said one cutter bladetoward said seating surface in said mounting slot and urges said supportmember into firm engagement with said seating surface in said mountingslot. .Iaddend..Iadd.
 29. A cutting tool assembly of the type that isfed in one direction into a workpiece during a machining operation toprovide on the workpiece when the machining operation is completed atleast two distinct surfaces, comprising: a cutter body having at leastone cutter blade mounting means opening outwardly from said cutter body,said mounting means having at least two locating surfaces at least inpart spaced from each other with at least one of said locating surfacesextending in a direction generally away from the outward opening of saidmounting means, first and second cutter blades each having a cuttingedge thereon and sidewalls extending generally rearwardly of saidcutting edge, said cutter blades being removably juxtaposed in saidmounting means between said locating surfaces thereof with said cuttingedges displaced from each other to each produce in said machiningoperation a respective one of said two distinct surfaces, means forurging said first cutter blade in a direction generally away from saidopening of said mounting means and generally opposite to said onedirection, each of said cutter blades having a respective pair of saidsidewalls disposed between said locating surfaces of said mounting meansand wherein said pair of sidewalls of said first cutter blade convergerelative to each other in a direction away generally rearwardly from theoutward opening of said mounting means and generally rearwardly from itscutting edge in a direction generally opposite to said one direction,with one of said converging sidewalls being juxtaposed with and bearingon one of the sidewalls of the other cutter blade so that urging of saidone cutter blade in a direction generally rearwardly from said openingof said mounting means and generally opposite to said one directionwedges both cutter blades against said locating surfaces of saidmounting means to firmly retain said cutter blades on said cutter body..Iaddend..Iadd.
 30. A cutting tool assembly as described in claim 29wherein said locating surfaces of said mounting means converge in adirection generally rearwardly from said opening of said mounting meansand generally opposite to said one direction. .Iaddend..Iadd.
 31. Acutting tool assembly as defined in claim 30 wherein said pair ofsidewalls of said other cutter blade are parallel to each other..Iaddend..Iadd.
 32. A cutting tool assembly of the type that is fed inone direction into a workpiece during a single step machining operationto provide on the workpiece when the single step machining operation iscompleted at least two distinct surfaces, comprising: a cutter body,first and second locating means on said cutter body spaced apart fromeach other, first and second cutter blades removably carried on saidcutter body, each of said cutter blades having a cutting edge thereonwith said cutting edges being displaced from each other to each producein said single step machining operation a respective one of said twodistinct surfaces, each of said cutter blades having a pair of wallsextending generally rearwardly of its cutting edge, the walls of saidfirst cutter blade converging relative to each other in a directiongenerally rearwardly from the cutting edge of said first cutter bladeand generally opposite to said one direction, said first and secondcutter blades being juxtaposed and wedged into engagement with eachother and said locating means with one of said converging walls of saidfirst cutter blade bearing on one of said locating means, the other ofsaid converging walls of said first cutter blade being juxtaposed withand bearing on one of said walls of said second cutter blade and theother wall of said second cutter blade bearing on the other locatingmeans, and means for retaining said first cutter blade in engagementwith said one locating means and said one wall of said second cutterblade so that both cutter blades are retained on said cutter body by awedging action of said first cutter blade. .Iaddend..Iadd.
 33. A cuttingtool assembly as described in claim 32 wherein said first and secondcutter blades are arranged and disposed relative to each other and tosaid locating means so that said first and second cutter blades arewedged into engagement with each other and said locating means by aforce on the first cutter blade having a component generally transverseto said cutting edge of said first cutter blade. .Iaddend..Iadd.
 34. Acutting tool assembly as described in claim 32 wherein said cutter bodyincludes a slot opening outwardly from said cutter body, said slothaving at least two sidewalls at least in part spaced from each otherand extending in a direction generally rearwardly from the outwardopening of said slot and generally opposite to said one direction, saidsidewalls of said slot forming said first and second locating means, andwherein said first and second cutter blades are arranged and disposedrelative to each other and to said sidewalls of said slot so that saidfirst and second cutter blades are wedged into engagement with eachother and said sidewalls of said slot by a force on said first cutterblade having a component in a direction inwardly of said outward openingof said slot and generally opposite to said one direction..Iaddend..Iadd.
 35. A cutting tool assembly as described in claim 34wherein said sidewalls of said slot converge relative to each other in adirection generally rearwardly from said outward opening of said slotand generally opposite to said one direction. .Iaddend..Iadd.
 36. Acutting tool assembly as described in claim 32 wherein said first cutterblade is arranged on said cutter body to be fed in a first directioninto a workpiece during a machining operation and wherein said first andsecond cutter blades are arranged and disposed relative to each otherand to said locating means so that said first and second cutter bladesare wedged into engagement with each other and said locating means by aforce on said first cutter blade having a component in a directiongenerally opposite to the direction in which said first cutter blade isfed into said workpiece. .Iaddend. .Iadd.
 37. A cutting tool assembly asdescribed in claim 32 wherein said first cutter blade is arranged onsaid cutter body to be fed in a first direction into a workpiece duringa machining operation and wherein said other converging wall of saidfirst cutter blade is disposed at an acute included angle to said firstdirection. .Iaddend..Iadd.
 38. A cutting tool assembly as described inclaim 32 wherein said cutter body has mounting means thereon opening ina direction outwardly of said cutter body, said mounting means includingsaid locating means, said locating means being disposed on said cutterbody inwardly of said outward opening of said mounting means and whereinsaid first and second cutter blades are arranged and disposed relativeto each other and to said locating means so that said first and secondcutter blades are wedged into engagement with each other and saidlocating means by a force on said first cutter blade having a componentin a direction inwardly of said opening of said mounting means andgenerally opposite to said one direction. .Iaddend.